This section provides background information related to the present disclosure which is not necessarily prior art.
Exhaust after-treatment systems generally comprise a catalyst component, such as a catalyst-coated exhaust treatment component, to treat the engine exhaust to remove harmful combustion by-products such as NOx, CO, and the like. During operation of the catalyst component, however, the catalyst component performance can be inhibited by the presence of water in the gas phase, as evidenced by an increase in light-off temperature with increasing water content in the gaseous exhaust. Although water content could be reduced through exhaust gas cooling and condensation, this process would require energy consumption for both condensation and gas reheating, which would be required for efficacy of the downstream catalyst component. Therefore, reduction of the water content in the gas exhaust without cooling the gas stream should significantly improve the light-off characteristics (and low-temperature performance characteristics) of several catalysts (in particular those for low-temperature methane oxidation, selective catalytic reduction of NOx (SCR), and lean NOx trapping and reduction (LNT).